Method of writing servo signal on magnetic tape

• US 6,771,450 B1
• Filed: 03/25/2002
• Issued: 08/03/2004
• Est. Priority Date: 02/17/1999
• Status: Expired due to Fees

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Okuda, Shinsuke, Ishii, Takashi
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): TZENG, FRED
• Application Number:
  US09/890,996
• Time in Patent Office: 862 Days
• Field of Search: 360/75, 360/69, 360/70, 360/71, 360/73.01, 360/73.02, 360/73.04, 360/73.05, 360/73.07, 360/74.2, 360/74.4, 360/74.5, 360/74.6, 360/48, 360/77.12, 360/77.13
• US Class Current: 360/75
• CPC Class Codes: G11B 5/584 for track following on tapes

Abstract

A method of writing servo signals on magnetic tape which comprises making a single laser beam (15) pass through a diffraction element (14) to split it into a plurality of beams (16) traveling in prescribed directions and then making the plurality of beams (16) pass through an optical convergence system (21) to form converged beam spots on a site of a magnetic tape (1) which is capable of forming servo tracks, the magnetic tape (1) being running at a prescribed speed, to cause the site to change physically or chemically thereby forming a plurality of servo tracks (S) in the longitudinal direction of the tape simultaneously.

Claims

1. A method of writing servo signals on magnetic tape which comprises making a single laser beam pass through a diffraction element to split it into a plurality of beams traveling in prescribed directions and then making said plurality of beams pass through an optical convergence system to form converged beam spots on a site of a magnetic tape which is capable of forming servo tracks, said magnetic tape being running at a prescribed speed, to cause said site to change physically or chemically thereby forming a plurality of servo tracks in the longitudinal direction of the tape simultaneously.

2. The method of writing servo signals on magnetic tape according to claim 1, wherein said optical convergence system comprises an fθ

lens.

3. The method of writing servo signals on magnetic tape according to claim 1, wherein said laser beam is split by said diffraction element into a plurality of coplanar beams making equal divergent angles with each other, and said beams, while passing through said optical convergence system, are formed into said converged beam spots aligned at a prescribed interval.

4. The method of writing servo signals on magnetic tape according to claim 3, wherein said converged beam spots are formed in such a manner that the direction in which said converged beam spots are aligned and the running direction of said magnetic tape make an angle larger than 0°

and smaller than 90°

.

5. An apparatus for writing servo signals on a magnetic tape which comprises a system for running a magnetic tape, a light source system for splitting a single laser beam into a plurality of beams, and an optical system for forming said plurality of beams into converged beam spots aligned at a prescribed interval on a prescribed site of said magnetic tape, wherein said light source system has a light source emitting said laser beam and a diffraction element which splits said laser beam into a plurality of coplanar beams making equal divergent angles with each other, said diffraction element being disposed so that the direction in which said converged beam spots are aligned and the running direction of said magnetic tape may make an angle larger than 0°

and smaller than 90°

.